diff --git a/tests/unit/test_documentation_consistency.py b/tests/unit/test_documentation_consistency.py
index c0ec7b6..8141811 100644
--- a/tests/unit/test_documentation_consistency.py
+++ b/tests/unit/test_documentation_consistency.py
@@ -115,6 +115,7 @@ TRAINING_M41_RELEASE_INDEX_GUARD_TEST_INVENTORY = (
     "test_training_m48_release_index_per_doc_helper_keeps_doc_tuple_shape",
     "test_training_m49_release_index_per_doc_helper_handles_empty_docs_without_mutation",
     "test_training_m50_release_index_helper_accepts_flattened_inventory_complete_doc",
+    "test_training_m54_release_index_required_snippet_inventory_category_shape_is_locked",
     "test_training_m53_release_index_doc_category_coverage_is_exact",
     "test_training_case_product_doc_reflects_current_m40_maturity",
 )
@@ -523,6 +524,9 @@ class DocumentationConsistencyTests(unittest.TestCase):
             "per_doc_helper_flattened_complete_doc": (
                 "test_training_m50_release_index_helper_accepts_flattened_inventory_complete_doc"
             ),
+            "required_snippet_inventory_category_shape": (
+                "test_training_m54_release_index_required_snippet_inventory_category_shape_is_locked"
+            ),
             "per_doc_helper_exact_category_coverage": (
                 "test_training_m53_release_index_doc_category_coverage_is_exact"
             ),
@@ -666,6 +670,7 @@ class DocumentationConsistencyTests(unittest.TestCase):
             "test_training_m48_release_index_per_doc_helper_keeps_doc_tuple_shape",
             "test_training_m49_release_index_per_doc_helper_handles_empty_docs_without_mutation",
             "test_training_m50_release_index_helper_accepts_flattened_inventory_complete_doc",
+            "test_training_m54_release_index_required_snippet_inventory_category_shape_is_locked",
             "test_training_m53_release_index_doc_category_coverage_is_exact",
             "test_training_case_product_doc_reflects_current_m40_maturity",
         )
@@ -788,6 +793,36 @@ class DocumentationConsistencyTests(unittest.TestCase):
         self.assertEqual(len(flattened_required_snippets), len(set(flattened_required_snippets)))
         self.assertEqual(missing_by_doc, {"synthetic-complete-release.md": ()})
 
+    def test_training_m54_release_index_required_snippet_inventory_category_shape_is_locked(self) -> None:
+        inventory = TRAINING_M41_RELEASE_INDEX_REQUIRED_SNIPPET_INVENTORY
+        expected_categories = (
+            "current_m1_m40_marker",
+            "acceptance_offline_validation",
+            "public_api_privacy_contracts",
+            "package_smoke_offline_registry",
+            "dashboard_public_docs_privacy",
+            "single_set_docker_deployment",
+            "docker_smoke_guard_coverage",
+        )
+        flattened_snippets = tuple(
+            snippet
+            for category in expected_categories
+            for snippet in inventory[category]
+        )
+
+        self.assertEqual(tuple(inventory), expected_categories)
+        self.assertEqual(len(expected_categories), len(set(expected_categories)))
+        for category in expected_categories:
+            with self.subTest(category=category):
+                snippets = inventory[category]
+                self.assertTrue(snippets)
+                for snippet in snippets:
+                    self.assertIsInstance(snippet, str)
+                    self.assertNotEqual(snippet, "")
+
+        self.assertEqual(TRAINING_M41_RELEASE_INDEX_DOC_SNIPPETS, flattened_snippets)
+        self.assertEqual(len(flattened_snippets), len(set(flattened_snippets)))
+
     def test_training_m53_release_index_doc_category_coverage_is_exact(self) -> None:
         inventory = TRAINING_M41_RELEASE_INDEX_REQUIRED_SNIPPET_INVENTORY
         expected_categories = tuple(inventory)